The Data Management Service makes lazy loading, paging and associations between types much easier to work with on the client, and it ties into the client-side SDK components very nicely. In many cases, the client code becomes nearly declarative, where you use a DataService to fill the root of your object model on the client and you bind that into your UI. From there, any changes to those objects are tracked automatically and can be committed or rolled back as batches (even across many associated types) with a single call to commit(). Batched commits to the server, along with lazy-loading data to the client and intelligent paging all help with performance and scalability.
The Data Management Service can also operate in an 'auto-sync' mode, where changes made by a client are automatically pushed out to other clients who are currently interacting with the same data. For collaborative applications or shared data models this is far more efficient than having clients poll the server to reset their views of the shared data to its current state. If you go the RemoteObject route you end up needing to write a lot more client code to handle these various concerns. For the upcoming LCDS release, Jeff has made the use of Hibernate with the Data Management Service even simpler and more automatic. Best, Seth ________________________________________ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of pradhasan Sent: Tuesday, January 22, 2008 8:47 AM To: [email protected] Subject: [flexcoders] Re: Hibernate.. Thanks for the update. I guess my question is not presented in correct way. Here I am explaining it. I want to know which one is better from the following options. 1) Flex Data Services(FDS) directly communicating with DMS. (2-tier architecture) 2) FDS communicating with Hibernate using RemoteObject service. (server side model - three tier architecture). The parameters we are looking in the above two options are performance & scalability. Thanks, --- In [email protected], "Seth Hodgson" <[EMAIL PROTECTED]> wrote: > > I'm not sure what you're asking. The Data Management Service in LCDS relies on an adapter layer to integrate into your backend. If your backend is a raw database, you may want to use the SQLAssembler for a quick prototype. If you have a Java domain model that uses Hibernate for persistence, use the HibernateAssembler. If you have some other backend (say an XML database or an in-memory data model accessed via a data grid API) you can write a custom assembler that would expose it to the Data Management Service so that Flex clients can interact with it simply and consistently using the client-side DataService component. > > It's not a matter of "Data Management Services Vs Hibernate". The Data Management Service is just providing a nice client-server API for plugging clients in to your backend data, which may or may not involve Hibernate. > > I'd recommend focusing on the server-side programming model you want to use for managing your data, and go from there. You'd have more opportunities for tuning (caching, write policies, etc.) using the HiberanteAssembler or a custom assembler than you have with the SQLAssembler which executes raw, parameterized queries against your database. > > Best, > Seth > > ________________________________________ > From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of pradhasan > Sent: Friday, January 18, 2008 2:29 PM > To: [email protected] > Subject: [flexcoders] Re: Hibernate.. > > In my Flex application with Weblogic appserver, which approach is > better for performance and transactions. Flex Data Management > Services Vs Hibernate. Apprecite your help. > > --- In [email protected], "Seth Hodgson" <shodgson@> > wrote: > > > > If you have an existing server-side domain model and are using > Hibernate use the HibernateAssembler. If you don't have any current > server-side code and just want to expose some tables in your > database to clients use the SQLAssembler. > > > > It really comes down to whether it makes sense for your client app > to be interacting with database tables directly, or whether you need > be interacting with server-side Java classes. > > > > Hope that helps, > > Seth > > > > ________________________________________ > > From: [email protected] > [mailto:[EMAIL PROTECTED] On Behalf Of pradhasan > > Sent: Friday, January 18, 2008 8:41 AM > > To: [email protected] > > Subject: [flexcoders] Hibernate.. > > > > Hi, > > > > I would like to know for large scale application which one is > better > > using HibernateAssembler or SQLAssembler in data-management- > config.xml. > > > > Thanks in advance. > > >
